156 research outputs found

    A GREAT TRAVEL OR THE NEW VIEW ON THE SETTLEMENT OF MENNONITES IN KHOREZM

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    In this article is given information about Mennonites who lived in the Central Asia, exactly in Khorezm region. In August 1881, a group of Mennonites called Trakt, arrived at Tashkent. They were accepted by Turkestan GeneralGovernor Kaufman. During their stay in the Central Asian territory they taught local people many interesting and useful job

    Study of the energy spectrum of primary cosmic rays: EAS size fluctuations at a fixed primary energy

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    During the initial period of the Samarkand EAS array operations the showers were selected on the basis of charged-particle flux density, and during the subsequent periods the showers were selected on the basis of Cerenkov light flux density. This procedure made it possible to measure the shower energy, to estimate the EAS size fluctuations at a fixed primary energy, and to experimentally obtain the scaling factor K(Ne, Eo) from the EAS size spectrum to the primary energy spectrum. Six scintillators of area S = 2 sq m each were added to the array. The fluctuations of EAS sizes in the showers of fixed primary energies and the scaling factors K(Ne, Eo) were inferred from the data obtained. The showers with zenith angles 30 deg were selected. The EAS axis positions were inferred from the amplitude data of the scintillators. The primary energy Eo was determined by the method of least squares for the known EAS axis position using the data of the Cerenkov detector located at 80 to 150 m EAS axis. It is shown that the Cerenkov light flux fluctuations at 100 m from EAS axis, q sub 100, do not exceed 10% at a fixed EAS energy, so the parameter q sub 100 may be used to estimate the EAS-generating primary particle-energy

    On the determination of the depth of EAS development maximum using the lateral distribution of Cerenkov light at distances 150 m from EAS axis

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    The Samarkand extensive air showers (EAS) array was used to measure the mean and individual lateral distribution functions (LDF) of EAS Cerenkov light. The analysis of the individual parameters b showed that the mean depth of EAS maximum and the variance of the depth distribution of maxima of EAS with energies of approx. 2x10 to the 15th power eV can properly be described in terms of Kaidalov-Martirosyan quark-gluon string model (QGSM)

    Heat Production Rate as an Indicator of the Ability of Plant Cell to Adapt to Environmental Conditions

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    The heat production rate in the suspension of unicellular alga (Chlorella vulgaris) was studied by the method of microcalorimetry during adaptation of the alga to stress conditions (NaCl and 45°C). The heat production rate slightly increased after the addition of 75 mM NaCl to cell suspension. A two-phase response was observed at 150 and 450 mM NaCl and at elevated temperature. The heat production rate was high during the first 3-4 h; then, it decreased and leveled off. This characteristic dramatically decreased at a high salt concentration (500 mM). Cell was unable to adapt to a high NaCl concentration (550 mM), which led to energy dissipation manifested in a high heat production rate. We conclude that the heat production rate, an integral indicator of plant cell activity can be used to assess plant cell adaptation to the impact of stress factors

    The use of concentrate from unprocessed beans in a fermented milk product

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    This article presents data on the production of concentrate from bioactivated beans for fortification of food products using concentrate with increased nutritional value, as environmentally safe food products. The technology of yogurt preparation included: enrichment with a bean center, as a food additive with a rich chemical composition in the form of powder - 5%, - 7%, - 10% and - 12%; preparation of berry filler in the form of strawberry jam with a content of 70% solids. In the course of studies to determine the dose and stage of application of bean concentrate by qualitative indicators, the best sample of the finished fermented milk product with a mass fraction of the added food additive of 7%, by weight of milk, was selected. The prototype of the germination duration for 48 hours had a high quality rating and received an average of 4.75 points (on a 5-point scale) in organoliptic indicators, which exceeded other options by 3 and 0.25 points. Analysis of the chemical composition of the bio-processed bean concentrate showed that its composition is rich in proteins (more than 21%), and also contains vitamins and minerals. According to the organoleptic and physico-chemical parameters of the finished product, it has been established that the enrichment of bean concentrate as a food additive is a promising direction in the creation of dairy products

    Effect of the Addition of Thermally Activated Heavy Loam to Portland Cement on the Properties of Cement Stone

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    © 2018, Pleiades Publishing, Ltd. In the past decades, metakaolin additives synthesized by the calcination of kaolin clays have been implemented in cement systems. Their scarcity and high cost promotes the studies on the effectiveness of thermally activated additives of common polymineral clays. This article presents the results of research on the effect of thermally activated heavy loam additives to Portland cement. It was shown that additives of 5–15% heavy loam calcined at certain temperatures in the range of 400—600°C and ground to a certain specific surface area of up to 250–500 m2/kg lead to a more significant increase in the strength, density, and water resistance of cement stone than corresponding metakaolin additives with the specific surface area of 1200 m2/kg

    Influence of limestone content, fineness, and composition on the properties and microstructure of alkali-activated slag cement

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    © 2016 Elsevier LtdThe influence of the fineness, concentration, and chemico-mineralogical composition of limestone on the workability, reaction kinetics, compressive strength, microstructure, and binder gel characteristics of sodium carbonate–based waste-activated waste slag cement pastes was investigated in this work. Alkali-activated slag cements incorporated with limestone, containing 33–100% of calcite, at a content of up to 60% with a 28-day compressive strength of 26.2–48.8 MPa were proposed. The main reaction products of hardened alkali-activated cement pastes and those incorporated with limestone are [Formula presented], CaCO3, Na2Ca(CO3)2·5H2O, and Na2CaSiO4. “Physically active” limestone does not chemically react with the binder gel but it can improve the physical structure. The higher packing density of mixed cement, without an increase in the water demand, the satisfactory binding strength of limestone with the binder gel lead to the improvement in the physical structure and compressive strength of alkali-activated slag paste

    Influence of the calcined light loam on the properties of the hardened portland cement paste

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    © 2017, Fundatia Serban Solacolu. All rights reserved. The increasing worldwide production of Portland cement and demand to reduce CO 2 emissions has resulted in the need to increase the volume and varieties of supplementary cementitious materials. The most promising source of raw materials for the production of supplementary cementitious materials is ubiquitous and unlimited reserves of polymineral clays. In this article the effect of calcined loam clays depending on its concentration, calcination temperature (400-800°C), and specific surface area (250-800 m 2 /kg) on the properties of Portland cement is studied. It is found out the calcined loam clays increase the compressive strength of Portland cement hardened paste up to 35%, density up to 1.4%, water resistance from 0.92 to 0.93-0.97, and decrease the water adsorption from 1 to 0.9%. The reasonability of production and application of calcined loam clays, which aren’t lower in efficiency than high-priced metakaolin, is stated

    Mechanism of solidification of simulated borate liquid wastes with sodium silicate activated slag cements

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    © 2017 Elsevier LtdIn this study the mineral matrix based on hydrous sodium metasilicate (NSH5) activated slag cement (AASC) was found to be suitable for solidification of borate solutions with pH 8.5–10.5 and concentration up to 200 g/L. Parameters such as setting times and compressive strength of the waste forms based on AASC and borate wastes can be influenced by the ratio of NSH5 and H3BO3 content. The dosage of 7% Na2O in the alkali activator per slag provides acceptable setting times and 28-day compressive strength of the waste forms in the range 49.7–56.1 MPa depending on pH of the borate solutions. Lowering the pH of borate solutions results in a reduced rate of setting of the fresh AASC paste, retardation in the structural formation of the hardened AASC paste, a reduced degree of hydration, and a reduction in the amount of calcium silicate hydrates and hydrotalcite. The product of AASC-based mineral matrix and simulated borate wastes interaction is ulexite (NaCaB5O6(OH)6(H2O)5)

    Study of the shower maximum depth by the method of detection of the EAS Cerenkov light pulse shape

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    The results of processing the data on the shape of the EAS Cerenkov light pulses recorded by the extensive air showers (EAS) array are presented. The pulse FWHM is used to find the mean depth of EAS maximum
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